Smwmed, Inc. · Class II · Cleared Apr 23, 2026
| K-number | K252389 |
| Device name | Rhythm Master ECG Patch (HM-15BB-AX, HM-15BW-AX, HM-15BW-DX) |
| Applicant | Smwmed, Inc. |
| Product code | DSH |
| Device class | Class II |
| Decision date | Apr 23, 2026 |
| Decision | Substantially Equivalent |
| Regulation | 870.2800 |
The Rhythm Master ECG Patch is a lightweight wearable cardiac monitoring device designed for continuous ECG recording. The HM-15BB-AX model records for up to 3 days while the HM-15BW-AX records for up to 7 days. It is indicated for patients 18 years or older who may be asymptomatic or experience transient symptoms such as palpitations, shortness of breath, dizziness, syncope, chest pain, and anxiety. Healthcare professionals apply and initialize the device; patients then wear it in home settings.
The device features a Type CF cardiac floating design with high-precision ECG monitoring (±10mV dynamic range, 0.5-40Hz frequency response), weighs 6.8 grams, and measures 37.0×22.5×7.7mm. It uses a rechargeable 3.6V lithium-ion battery. The HM-15BB-AX transmits data via Bluetooth Low Energy to smartphones; the HM-15BW-AX uses USB Type-C for computer connectivity. The device provides heart rate, heart rate variability, and accelerometer data for reference purposes and allows physicians to view recorded ECG waveforms, but does not perform automated analysis or real-time monitoring.
Biocompatibility: ISO 10993-1, 10993-5, 10993-10, 10993-23. Electrical safety: IEC 60601-1, 60601-1-2, 60601-1-11, 60601-2-47, 62133-2. Software: IEC 62304 and FDA guidance on device software functions. Security: FDA cybersecurity guidance. ECG electrodes: ANSI/AAMI EC12:2000. Wireless: ANSI/USEMCSC C63.27:2021 and ANSI TIR 69:2017.
The device has identical intended use, indications, and regulatory classification (Class II, DSH product code) as the two predicate devices (S-Patch Ex and ePatch®). Technological characteristics including ECG dynamic range, patch form factor, recording format, and data storage are substantially similar. Minor differences (battery type, communication protocols, software platform, wear time) do not raise safety or efficacy concerns. Performance testing demonstrates compliance with the same consensus standards as predicates, supporting substantial equivalence.
View the full FDA submission: accessdata.fda.gov